OAK RIDGE, TENN. - Scientists working for the Department of Energy have developed an electrochemical process to convert carbon dioxide (CO2) into ethanol.

Oak Ridge National Laboratory said the team used nano-spike catalysts to convert the greenhouse gas into a fuel. The catalyst was comprised of carbon, copper and nitrogen, and a voltage was applied “to trigger a chemical reaction that essentially reverses the combustion process.” The nanoscale structure consists of copper nanoparticles embedded in carbon spikes that are roughly 50 nanometers tall (0.00000005 meters).

“We discovered somewhat by accident that this material worked,” said ORNL’s Adam Rondinone, lead author of the team’s study published in ChemistrySelect. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”

Using the catalyst, Oak Ridge said the solution of carbon dioxide dissolved in water turned into ethanol with a yield of 63 percent. Rondinone noted they have measured a yield as high as 70 percent.

“We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backwards with very high selectivity to a useful fuel,” Rondinone said. “Ethanol was a surprise -- it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

Researchers believe the low-cost materials and ability to operate the process at room temperature could lead to the method being scaled up for industrial applications. One such application, Rondinone suggested, would be using excess electricity generated from solar and wind to power the process and create ethanol.

“A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol,” he said. “This could help to balance a grid supplied by intermittent renewable sources.”

ORNL said the researchers plan to try and improve the production rate and study the catalyst’s properties and behavior. Oak Ridge added the work was supported by the Department of Energy’s Office of Science and used resources at the ORNL’s Center for Nanophase Materials Sciences.